Cysteine and related aminothiols in cardiovascular disease, obesity and insulin resistance.

Cysteine, homocysteine, glutathione and cysteinylglycine are metabolically related low molecular weight aminothiols involved in antioxidant defense and in thiol redox control in many cellular and extracellular processes. Alterations in plasma aminothiol profiles are evident in pathologic conditions associated with oxidative stress and accordingly can be considered potential biomarkers. More recently, cysteine has received special attention on this regard and several methodologies for the separation and measurement of cysteine as well as other related aminothiols have been developed and refined. In this review, we provide insight into characteristics, biologic functions, and metabolic interactions of aminothiols (including their involvement in thiol redox status). We highlight cysteine and review methodologic approaches to elucidate its potential role as a risk factor as well as a biomarker in cardiovascular disease, obesity and insulin resistance.